Transfer subscribers from ORG to COM-no jetpack

I would like to move about 500 subscribers from a self-hosted site to a site I am setting up on com. I've read earlier forum discussions where when this was done, they were being moved with jetpack. I don't have jetpack on my self-hosted site and installing it is not an option.

The newsletter program I'm using generates either a text or CSV file. Would it still be possible to move them?

auxclass-no, unfortunately. There is currently a separate feedburner signup on the org site for those that prefer to get notifications by RSS. I do know I can add the RSS feed widget to the site's sidebar on com, but we'll see.

Was hoping to make the transition to Com as seamless as possible, but this is kind of a big stumbling block. Thanks again for your time and answers.